1. Field of Invention
This invention relates to filling a printbar with ink. More particularly, this invention is directed to methods and apparatus that initially fill the printbar, such as a full width array printbar, with ink using positive pressure.
2. Description of Related Art
Thermal ink-jet printers generally include a plurality of thermal printheads for ejecting ink onto a recording medium, such as, for example, paper. Each thermal printhead has a resistor to selectively vaporize ink near the nozzle of a capillary-filled ink channel. The vaporized ink forms a bubble that temporarily expels an ink droplet and propels it toward the paper. These types of thermal heads are incorporated in either a carriage-type printer or a page width or full width array (FWA) type printer.
U.S. Pat. No. 5,359,356 to Ecklund describes the use of a slidable primer rod featuring a plunger which uses gravity to assist in collapsing a flexible ink bag for an ink jet printer. The only force applied to the ink container is the weight of the rod and plunger. U.S. Pat. No. 5,621,445 to Fong et al. and U.S. Pat. No. 4,714,937 to Kaplinsky also describe printers featuring flexible ink containers. U.S. Pat. No. 4,240,052 to Yu describes a momentumless shutdown of a jet drop printer in which a positive pressure is created in an ink manifold by a pump located prior to the manifold.